Original Post
3D viewer.
Remember this?
Wouldn't blame you if you didn't. This was implemented in 2015 for one event hosted by GMs & IFs and then forgotten about completely after prizes were distributed.

Considering the overhaul of the forums, how about integrating a simple yet helpful 3D viewer under each texturable item's "Edit" link on the forums that works on mobile as well?
More specifically, a total of 21 objects for each of the bodypart/joint combo (i.e head + neck joint | hand + wrist | stomach + chest etc.)
As for the 3D items, they would be simple to implement as it can grab the .OBJ and .TGA from cache.tb's depository and view it.

No need to code from scratch, there are dozens of published open source engines on Github, most notable of which being Google's Model-Viewer that is used by many websites & applications for augmented reality and 3D viewing.

And no this is not a replacement for TBTextures, as it would view texturable 3D items of all types; not just the body and joint textures (and maybe non-texturable as a way to embed previewing in posts whenever releasing an item? would remove the need of many screenshots.)